Adjustable standing lamp



FIG. 1 is a top and left perspective view of an adjustable standing lamp showing my new design;

FIG. 2 is a bottom and right side perspective view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a side elevational view thereof, the opposite side being a mirror image;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a front elevational view thereof. 

The ornamental design for an adjustable standing lamp, as shown and described. 